Bioabsorbable magnesium alloy with controlled multi-phase absorption
AssigneeMagsorbeo Biomedical Corp.
InventorsJacob Edick, Carolyn Woldring
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Abstract
A bioabsorbable magnesium alloy for use in an orthopedic implant comprises magnesium, zinc in an amount of 0.5-4 weight percent, calcium in an amount of 0.1-1.5 weight percent, and manganese in an amount of up to 1.5 weight percent. The alloy exhibits a controlled, multi-phase absorption profile when exposed to physiological conditions, including an initial period of minimal degradation, followed by a steady-state phase, and concluding with an accelerated absorption phase. A method of manufacturing the alloy includes casting, solution treating, and extruding. An orthopedic implant device formed from the alloy comprises a body that exhibits the controlled, multi-phase absorption profile when implanted.
Claims18
A bioabsorbable magnesium alloy for use in an orthopedic implant, comprising:
- magnesium;
- zinc in an amount of 0.5-4 weight percent;
- calcium in an amount of 0.2-10 weight percent;
- and
- manganese in an amount of 0.5-1.0 weight percent;
- wherein the alloy comprises a microstructure having a Mg2Ca phase and ternary intermetallic phases;
- wherein the Mg2Ca phase comprises less than 1.0 wt % of the alloy;
- wherein an average diameter of Mg2Ca phase precipitates is less than 200 nanometers (nm);
- wherein the alloy forms a protective oxide layer when exposed to physiological conditions;
- and
- wherein the alloy exhibits a controlled, multi-phase absorption profile when exposed to physiological conditions, the profile comprising an initial period of minimal degradation, followed by a steady-state phase, and concluding with an accelerated absorption phase.
A bioabsorbable magnesium alloy for use in an orthopedic implant, comprising:
- magnesium;
- zinc in an amount of 0.5-4 weight percent;
- calcium in an amount of 0.2-1.0 weight percent;
- and
- a third alloying element in an amount of 0.1-1.0 weight percent;
- wherein the alloy comprises a microstructure having:
- a ternary intermetallic phase with a volume fraction between 0.5% and 5%;
- the ternary intermetallic phase having an average particle size between 50 nm and 500 nm;
- and
- Mg2Ca phase present in a volume fraction of less than 1% with an average particle diameter of less than 200 nm;
- wherein the alloy exhibits a controlled, multi-phase absorption profile when exposed to physiological conditions, the profile comprising an initial period of minimal degradation, followed by a steady-state phase, and concluding with an accelerated absorption phase.
An orthopedic implant device, comprising:
- a body formed from a bioabsorbable magnesium alloy, the alloy comprising magnesium, 1-4 weight percent zinc, 0.2-1.0 weight percent calcium, and 0.3-1.0 weight percent manganese;
- wherein the alloy comprises a microstructure having a lower amount of Mg2Ca phase relative to ternary intermetallic phases;
- wherein the ternary intermetallic phases comprise Ca2Mg6Zn3 and have a volume fraction between 0.5% and 5%,
- wherein the alloy forms a protective oxide layer when exposed to physiological conditions, the protective oxide layer having a thickness between 10 nm and 500 nm;
- and
- wherein the alloy exhibits a controlled, multi-phase absorption profile when exposed to physiological conditions, the profile comprising an initial period of minimal degradation, followed by a steady-state phase, and concluding with an accelerated absorption phase.
Dependencies are inferred from the claim text.